JPS63169420A - Combustion control device - Google Patents

Abstract

PURPOSE:To reduce an amount of a noxious substance exhausted during ignition and to reduce an amount of nitrogen oxide generated during stable combustion, by a method wherein ignition to a burner is effected by low air ratio ignition, and by increasing a feed air amount immediately after ignition, a burner is transferred in a state of high air ratio combustion. CONSTITUTION:By means of a signal from a combustion amount transmitting part 12, fuel is fed through a pump drive circuit 17 to a burner 1 with the aid of a fuel pump 3. In this case, an air switching valve 14 receives a signal from a shift transmitting part 15 to bring an air port 13 into a opening state by means of a switching valve drive circuit 18, and air is fed to an evaporating cylinder 5 in an air ratio of a value being lower than 1.0 and is fed to a burner 1, and thereby ignition is facilitated. When the ignition is detected in a flame detecting part 19 by means of an ion current from a flame rod 9, a signal therefrom, simultaneously, is outputted to a shift transmitting part 15. The air switching valve 14 is actuated through the working of the switching valve drive circuit 18, and the air port 13 is instantaneously closed. With this constitution an air amount which is slightly higher than a theoretical air amount of fuel is fed to create a complete combustion state, and an amount of an noxious exhausted substance, e.g. carbon monoxide is reduced to an extreme low value.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a combustion control device that controls the air ratio at the time of ignition in a combustion device that uses gas or oil as fuel and performs primary combustion.

Conventional Technology In this type of all-fire combustion equipment, the amount of air is set at an air ratio of 1.0 or more, which is greater than the theoretical air amount. It has the advantage of significantly lowering the flame temperature by reducing the combustion rate, which greatly reduces the generation of nitrogen oxides such as NO2 and NOx, which are said to have a negative impact on the human body. Ta.

However, on the other hand, the higher the air ratio at the time of ignition, the lower the fuel concentration, which makes it difficult to ignite instantly, takes time to ignite, or even fails to ignite. Toxic emissions (i.e. carbon oxides, hydrocarbons, carbon dioxide, etc.) due to delays, etc.
Oh, it's so easy.

Ta. For this reason, a method has been considered in which the amount of combustion air is controlled to below the theoretical air amount of the fuel at the time of ignition, and the amount of air is increased after ignition to shift to steady combustion at a high air ratio.
Generally, combustion air is supplied by a blowing fan, so it is difficult to rapidly control the air ratio due to a response delay in rotation speed, etc., and a combustion state where the air ratio is below 1.0 will exist for a while due to this response delay. As a result, large amounts of harmful substances such as carbon monoxide and hydrocarbons were generated. For this reason, conventional combustion equipment of this type has been equipped with a switching valve in the combustion air supply path to quickly switch the air ratio. The combustion control was such that the air ratio was suppressed and rapidly shifted to a high air ratio (air ratio of 1.0 or more).

(For example, Japanese Unexamined Patent Publication No. 57-16421 C1) Problems to be Solved by the Invention However, in the above configuration, the temperature near the burner flame hole increases because the air ratio is changed from a low air ratio to a high air ratio at once at the time of ignition. is not rising sufficiently, the flame is unstable, and
It was easy to cause the phenomenon of As a result, the generation of toxic emissions due to incomplete combustion increased significantly, and there was a risk of misfire occurring, which was extremely harmful to the human body.

The present invention solves these conventional problems by significantly suppressing the amount of toxic emissions (carbon oxides, hydrocarbons, etc.) generated during ignition, and suppressing the amount of nitrogen oxides (NO2, NO2, etc.) generated during stable combustion.
An object of the present invention is to provide a combustion control device for a full-fire combustion burner in which the occurrence of x) is reduced.

Means for Solving the Problems In order to solve the above problems, the combustion control device of the present invention includes:
An all-primary combustion burner, a fuel supply means 11 for supplying fuel to this burner, an air supply means for supplying combustion air, an air path for guiding combustion air supplied from the air supply means to the burner, and this air An air switching valve that switches a part of the combustion air provided in the path to an open state to the outside, a flame detection means that detects the flame state of the burner, and a controller that drives and controls the fuel supply means and the air supply means, A part of this control includes an air amount transmitter that transmits a signal of the amount of air supplied to the air supply means, a combustion amount transmitter that transmits a signal of the combustion amount to the fuel supply means, and a signal from the flame detection means. a switching transmitter that receives the signal and sends a signal to the air switching valve to release a part of the combustion air to the outside when there is no flame, and a signal to send the entire amount of combustion air to the burner when a flame is formed; The air amount transmitter sends a signal that sends an air amount slightly higher than the theoretical air amount of the fuel at the time of ignition, and after ignition, the air amount is gradually increased to a constant air amount that is slightly higher than the theoretical air amount of the fuel. The structure is such that the signal is transmitted to the air supply means as shown in FIG.

Effect The present invention has the above-described configuration, which significantly reduces the amount of toxic emissions (carbon oxide, hydrocarbons, etc.) generated during ignition, and suppresses the generation of nitrogen oxides during stable combustion, resulting in a total primary combustion system that is harmless to the human body. This makes it possible to provide a combustion control device for a combustion burner.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In the embodiment, an indoor open combustion hot air heater (oil 7 unheater) using a petroleum vaporizing burner will be described as an example.

FIG. 1 shows a system block diagram of the present invention.

1 is a burner; fuel is supplied from a fuel tank 2 to a fuel pump 3 through a multi-fuel nozzle 4 to a carburetor tube 5; The premixed gas is vaporized and mixed within the combustion chamber, and is supplied as a premixed gas to the burner 1 to form a combustion flame 8. Reference numeral 9 detects the ionic current in the combustion flame 8 with a flame rond, and detects the flame state. A controller 10 controls these combustions. This controller 10 includes an air amount transmitting section 11 that transmits a signal of the amount of combustion air to be supplied to the blower fan 6.
A signal is sent to the combustion amount transmitter 12 that sends a combustion amount signal to the fuel pump 3, and the air switching valve 14 that opens and closes the air port 1b in the air path 7 that releases a part of the combustion air to the outside. It has a switching transmitter 15 for transmitting data. At the time of ignition, multiple signals are transmitted from the air amount transmitter 11 to the combustion air, and the combustion air is supplied to the burner 1 through the fan drive circuit 16 by the air blower 7A 6. On the other hand, the fuel is supplied to the burner 1 by the fuel pump 3 after multiple signals are transmitted from the combustion amount transmitter 12 and passes through the pump drive circuit 17 . At this time, each signal is transmitted at a ratio of combustion air to fuel, ie, an air ratio slightly greater than 1.0. However, at this time, the air switching valve 14 receives the signal from the switching transmitter 15 and causes the switching valve drive circuit 18 to open the air port 13, so that the air ratio is less than 1.0. In other words, a smaller amount of air than the theoretical amount of air for fuel is being sent to the carburetor cylinder 5, and a premixture rich in fuel is supplied to the burner 1, so that it can be easily ignited. However, since combustion in this state is an air-deficient state, the fuel is not completely combusted, producing harmful carbon monoxide and hydrocarbons. Therefore, at this time, the ignition is detected by the flame detection section 19 using the ion current from the flame rod 9, and at the same time, a signal of this flame detection is sent to the switching transmission section 15, and the signal from the switching transmission section 15 is transmitted via the switching valve drive circuit 18. The air switching valve 14 is activated to instantly close the air port 13. As a result, during combustion immediately after ignition, an air amount slightly higher than the stoichiometric air amount of the fuel is suddenly supplied, and toxic emissions such as sea oxide carbon during complete combustion are extremely reduced.

Furthermore, Fig. 2 shows the amount of C◯ generated depending on the air ratio in the case where secondary air hardly contributes to combustion.

At the same time, when the flame detection section 19 roughly detects ignition, the air amount transmitting section 11 receives this flame detection signal and gradually increases the air amount to set a constant air amount (slightly higher than the theoretical air amount of the fuel). Send a signal to the air blower 7 An 6 so that the air ratio is a high air ratio in the stable combustion region (this value differs slightly depending on the type of burner, but in general, the air ratio is about 1.5 for a full-fire combustion burner). As a result, a high air ratio is reached when the temperature near the flame opening of burner 1 has risen sufficiently, making it possible to transition from ignition to steady combustion with a stable flame (combustion occurs near the theoretical air amount). The combustion speed is the fastest, the flame temperature rises easily, and the atmosphere temperature rises easily.However, as the amount of air increases, the combustion speed decreases and the flame temperature becomes lower, and cooling by the air itself (The temperature near the burner nozzle is difficult to rise.) Therefore, no lift phenomenon is observed due to insufficient temperature rise at the burner nozzle, and as a result, the amount of carbon monoxide generated is significantly reduced, and during stable combustion. Safe combustion with extremely low nitrogen oxide production can be achieved. Note that FIGS. 3 and 4 show the state of Co generation after ignition in the case of combustion control using a conventional air path switching valve and in the case of combustion control according to this embodiment.

Effects of the Invention As described above, the combustion control device of the present invention provides the following effects.

1) The burner is ignited smoothly by low air ratio ignition, and the amount of air supplied is immediately increased after the combustion is completed, and the combustion shifts to high air ratio combustion. , odor, etc.) is significantly suppressed.

2) Immediately after ignition, after increasing the air ratio to 1.0 or more,
Since the combustion state gradually shifts to a higher air ratio, the flame is always stable, the generation of toxic emissions due to lift phenomenon etc. is significantly suppressed, and the production of nitrogen oxides is extremely low during stable combustion, which is extremely safe for the human body. Able to provide safe combustion conditions.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a combustion control device showing an embodiment of the present invention, Fig. 2 is a combustion characteristic diagram of a primary burner, Fig. 3 is an ignition characteristic diagram of a conventional combustion control device, and Fig. 4 is a diagram of ignition characteristics of a conventional combustion control device. FIG. 3 is an ignition characteristic diagram of the combustion control device of this embodiment. 1... Burner, 3... Fuel pump, 6
...Blower fan, 9...Frame rod, 10...Controller, 11...
Air amount transmitting section, 12...Fuel transmitting section, 14...
...Air switching valve, Agent's name: Patent attorney Toshi Nakao, male Haka100
Deep and shallow g4 reward CA Nz
figure

Claims (1)

[Claims] an all-primary combustion burner, a fuel supply means for supplying fuel to the burner, and an air supply means for supplying combustion air;
An air path for guiding combustion air supplied from the air supply means to the burner, an air switching valve provided in the air path for switching a part of the combustion air to an open state to the outside, and detecting a flame state of the burner. The controller includes a flame detection means, and a controller that drives and controls the fuel supply means and the air supply means. A combustion amount transmitting section that transmits to the fuel supply means and a signal from the flame detection means send a signal to release a part of the combustion air to the outside when there is no flame, and send a signal to the burner when a flame is formed. It has a switching transmitter that sends a signal to the air switching valve, and the air amount transmitter sends a signal that sends a slightly larger amount of air than the theoretical air amount of the fuel at the time of ignition, and gradually reduces the air amount after ignition. A combustion control device that sends a signal to the air supply means to increase the amount of air to a constant amount that is significantly greater than the theoretical amount of air in the fuel.